Packaging machine



Sept. 27, 1960 G. w. TEW

PACKAGING MACHINE 6 Sheets-Sheet l Filed May 8, 1959 Ulmunllllmvl l NTOR.

A rrok/VE Ys Sept. 27, 1960 Q w, TEW 2,953,882

PACKAGING MACHINE Filed May 8, 1959 6 Sheets-Sheet 2 I i rn' l INVENToR.

A TTNE YS Sept. 27, 1960 G, w TEW 2,953,882

PACKAGING MACHINE Filed May 8, 1959 6 Sheets-Sheet 5 Sept' 27, G. W. TEWPACKAGING MACHINE Filed may e, 1959 6 sheets-sheet 4 E N T MUM@ m/ sept.27, 1960 G. w. TEW 2,953,882

PACKAGING MACHINE Filed May 8, 1959 6 Sheets-Sheet 5 INVENTOR.

A T TORNE YS Sept. 27, 1960 G. w. TEW

PACKAGING MACHINE 6 Sheets-Sheet 6 Filed May 8, 1959 m. w w w HTTOKNEYSUnited Statt-s Patent 2,953,882 PACKAGING MACHINE Gilbert W. :Iew,Durham, N.C., assignor to Sperry Rand Corporation, Wilmington, Del., acorporation of Delaware Filed May s, 1959, ser. No. 811,867

claims. (Cisa-126) periodically drawn through the tube-forming means,

lled with successive charges of product, transversely sealed andsevered. The means for periodically drawing the tube through the formercomprises a pivoted arm having relatively movable gripping andtransverse sealing jaws thereon. The swinging arm or draw bar thusreciprocates about a fixed `axis and its jaws 'are automaticallyactuated to grip the tube as the arm starts its downward movement and toform la transverse seal during such downward movement. The machine alsoincludes clipper elements adapted to pinch the tube from opposite sidesafter the product has been placed therein to fracture any of the productthat extends up into the zone in which the next transverse seal will beformed. The clipper elements of this invention are novel in constructionand relationship to the rest of the machine and are readily adapted todiiferent types of operation.

The pivoted draw bar is preferably operated by a reciprocatory liuidmotor, although other forms of driving mechanism may be employed, but isso driven that ICC packaging of products heretofore dilicult to packageat' high speeds. Y

Still another object of this invention is to provide a.

machine of the type set forth embodying novel con# struction featureswhereby the machine is readily adapted'. to different types of cyclesand for producing different.` lengths of bags without making anystructural changea.

adjustments or substitutions.

A further object is to provide a packagingr machine.

of the type set forth involving a novel draw bar arrangement, novelclipper devices, and a novel relationship between the draw bar andclipper devices. I

A still further object is to provide a packaging machine as set forthembodying a novel clipper construc tion and operating meanswhereby theoperation of the. clippers may be varied at will without` makingmechanical,y adjustments or changes in the machine.

Additional and further objects and advantages will become apparent tothose skilled in the art as the de scription proceeds in connection withthe accompanying drawings, wherein: p v

Fig. 1 is a side elevational view of a machine embodying the presentinvention with certain .parts thereof broken away to facilitateillustration and other parts shown in a somewhat schematic manner;

Fig. 2 is an end elevational view of the machine of Fig. 1 as viewedfrom the left end of Fig. l;

Fig. 3 is a fragmentary sectional view, on an enlarged scale, takenalong the line 3 3 of Fig. 2;

Fig. 4 is a horizontal sectional view taken along line 4-4 of Fig. 3; i

Fig. 5 is a vertical sectional view, on a further en# larged scale,taken along the line 5-5 of Fig. 3;

Fig. 6 is a View taken along the line 6-6 ofFig. 2, showing the parts inenlarged scale; j

Fig. 7 is an enlarged horizontal sectional view taken substantiallyalong the line 7-7 of Fig. 2; Y

the driving means need not 'always operate Ythrough a lforming materialinto hollow tubular form without the use of internal mandrels or thelike. Product-directing means direct the successive charges of productinto the tube as it is being formed and the delivery of the charges ofproduct thereto are so timed and controlled that they enter the tubejust as the draw bar starts to drawmore material through thetube-forming device. Thus, there is very little tendency for the productto bridge across the entry to the formed tube.

Y 'Ihe machine also includes a reciprocatory plunger operated in timedrelationship to the cycles of the draw bar and to move downwardly intoafeed hopper directving the product into the tube just after the producta machine for more efficient and rapid packaging and sealing of certainproducts.

, Another object is to provide a machine for the rapid Fig. 8 is anenlarged fragmentary sectional view taken along the line 8--8 of Fig. 2;A

Fig. 9 is an enlarged view of the control cam 4assembly as seen alongthe line 9 9 of Fig. y2 but-on .an enlargwd scale;

Fig. l0 is a transverse sectional view ltaken along the line 10-10 ofFig. 9; j

Fig. l1 is a composite ligure consisting of a series of schematicsketches illustrating sequential steps in a cycle of operation of themachine of this invention; and

Fig. l2 is a schematic perspective illustration of an |alternative formof machine embodying the principles of the present invention and shownwith certain parts broken away to facilitate illustration. n f j Themachine of the present invention finds particular utility in thepackaging of products such as'potato chips or the like and enables thepackaging thereof atjunusuallyhigh speeds and in a reliable andefficient manner. However, the invention is not limited to machines forpackaging potato chips or any other particular product even though thedescription herein will be made lwith reference to potato chips or thelike as theparticular packages are to be formed. The material may bepaper or plastic film or any other suitable web material'capable ofbeing handled in the manner described. "The rwel? Patfnted Sept. 27,1960 material 6 is guided through suitable guiding rolls and the like toa tube former 8. The tube former 8 is designed to guide and direct theweb 6 to the interior of the hollow tubular guide portion 10 without thebenefit of internal mandrels and leaving the interior of the formed tubefree of obstructions. The hopper 2 is configured, at its lower end 12,to conform closely to the shape of the end of the formed tube at theentrance end of tubular guide 10. From the tube former 8 the formed tubeextends downwardly past a longitudinal sealing device 14 adapted toheat-seal the longitudinal edges of the web to form a longitudinallyseamed tube extending downwardly from the tube former 8.

` A draw bar assembly 16 includes an arrn 18 pivoted about a xed axis 20on the machine frame and carrying transverse Sealing jaws 22 (Fig. 1)pivotally mounted thereon for opening and closing movements on oppositesides of the formed tube previously referred to. A hydraulic motor 24eiects swinging movements of the arm 18 and mechanism to be describedlater effects simultaneous pivotal movements of the jaws 22 to open orclosed position. `Clipper devices 26 are arranged with movable clipperelements on opposite sides of the formed tube and movable to approacheach other and to flatten the tube between them after the product hasbeen deposited therein. 'Ihus the clippers fracture or break any potatochips or the like extending upwardly to such a degree that they wouldinterfere with the end seal of the bag. The clippers are then opened topermit any fragments of the chips to fall into the bag and the jaws 22may then be closed and the draw bar 18 lowered to advance the webmaterial and form a further section of tube. During `its downwardmovement the draw bar zssembly. moves past a fixed cam arrangement thateects severing of the filled and sealed bag portion from the end of theformed tube and such lled and sealed bag is nally dropped onto atake-away conveyor 28 for delivery to a desired delivery station.

The machine shown in IFig. l makes provision for supporting an adequatesupply of web material. A plurality of spindles 30 are mounted to extendoutwardly from a side plate 32 of the machine with their outer endsunsupported and thus the spindles 30 are adapted to have reels 34 easilyapplied thereto or removed therefrom. Each of the spindles 30 isthreadedly supported by the plate 32 and is provided with a knurledouter end portion 36 (see Fig. 2). ly lifting the outer end of a shaft30, rotate the same to threadedly adjust it in an axial direction andthus provide for proper tracking adjustment of Ithe web 6 as it iswithdrawn from a reel 34. Suitable removable flange what greater detailin Fig. 8.

Thus the operator may, by slightg devices 38 (Fig. 2) are provided tohold the reels 34 on their respective shafts 30. Each of the reels 34 isprovided with a brake device 40 (only one of which is shown in Fig. 1)pivoted at one end to the machine frame at 42 and having a weight 44 atits other end to control the tension in the web drawn therefrom.

From the particular reel being used at the time, the web is fed overidler rolls 45 and movable tension rolls 46 past a photoelcctricregistering device 48. The tension rolls 46 are carried by a spring arm50 mounted on the machine frame and operable to maintain tension in theweb 6 at all times. With the reel arrangement shown multi-ply bags maybe formed by feeding material from more than one reel at the same time.

After the web 6 passes photoelectric device 48 it is directed overfurther guide rolls 52 and onto the guiding hood 54 of tube-formingdevice 8. The tube-forming member 8 does not constitute a part of thepresent invention and so will not be described in detail herein. As theweb 6 first engages the hood 54 .it is also engaged by friction rollers56 (only one shown in Fig. 1) carried at the outer ends of arms 58pivotally mounted on plate 32, at 60. The rollers 56 are preferablyprovided with rubber or the like peripheries and are rotatably mountedon the arms 58 through one-way clutch devices whereby the rollers 56rotate freely ima forward direction to permit feed of the web 6 to thetube former 8 but frictionally prevent movement of the web 6 in theopposite direction.

Since the brake devices 40 cause the web 6 to be held under tension, thespring arm S0, carrying tension rollers 46, will at all times bedeliected downwardly to a certain degree depending on the amount oftension predetermined by the brake devices. If it were not for theone-way clutch arrangement in rollers 56, the web 6 could be withdrawnback toward the supply by the stressed spring arm 50 and thus draw theformed tube back up toward the tubular guide 10 when the jaws 22 releasethe tube at the end of each cycle. However, the rollers 56 prevent suchretrograde movement and the formed tube remains stationary when releasedby the jaws 22. The photoelectric registering `device 48 is preferablymounted on the machine plate 32 in such manner that it may be adjustedso as to properly detect spaced marks of the web 6, spaced apart adistance corresponding to the length of the bags to be formed therefrom.The purpose and operation of this registering device will be discussedin greater detail later.

As the web 6 is guided and directed by the tube former 8 into hollowtubular form, it is further so controlled and directed that itslongitudinal edges overlap at the left side of the tube former seen inFig. l and shown in some- The tube former 8 is carried by a bracket 62removably mounted on the machine frame whereby tube formers may bereplaced with formers for bags of diierent diameters. The bracket 62further supports a backing bar 64 of paramagnetic material and arrangedto extend downwardly inside the formed tube inwardly of the overlappinglongitudinal edges of the web material. As shown in Fig. 8, the backingbar 64 is of reduced section at its upper end portion 66 whereby theupper cnd portion is relatively exible.

The longitudinal heat-sealing assembly 14 is shown in section in Fig. 7and comprises a pair of side or pole plates 68 of paramagnetic materialand so contigured that their forward edge portions 70 extendlongitudinally of the formed tube and directly opposite the backing bar64 inside the formed tube. Between the spaced edges 70 of the plates 68is a non-magnetic heatconducting body 72 having a suitable heat element76 therein and a thermostatic control element 74. At longitudinallyspaced positions along the heat sealer 14, the plates 68 are securedtogether by bolts 78 passing through spacer members of paramagneticmaterial. About each spacer member 80 is an electrical coil 82. Asevident from Fig. 1, a plurality of the coils 82 are provided in theassembly 14. When the coils 82 are energized by having direct currentpassed therethrough, an electromagnet is produced which attracts thebacking bar 64 and firmly clamps the overlapping longitudinal edges ofthe formed tube between the heated body 72 and backing bar 64 toheat-seal the tube under pressure. When the coils 82 are de-energizedthe resilient neck portion 66 of the backing bar 64 causes the backingbar to move away from the edges 70 and heated body 72 suiiiciently toprovide adequate clearance for longitudinal movement of the formed tubein a downward direction withoutl dragging on either bar 64 or edges 70.The longitudinal heat-sealing assembly 14 constitutes the subject matterof an independent invention more fully described and claimed in acopending application. The longitudinal heat sealer 14 is shown in Fig.7 as being mounted on a supporting arm 84 pivotally mounted on themachine so that it may be completely withdrawn from the tube former oradjusted in a radial direction. The mounting and adjustment of thelongitudinal heat sealer is more fully described in the copendingapplication re- .ferred to.

The pivoted draw bar 18, and particularly the outer S end portionthereof, is shown in greater detail in Figs. 3 through 5, to whichreference is now made. In Figs. 3 4 and 4 numeral 18 designates the maintubular arm portion of the draw bar and is shown supporting a headcasting 86 fixed thereto by transverse bolts 8S. Parallel transverseshafts 90 are journalled in the head casting 86 and each shaft isprovided with a pair of upstanding arms 92 at its ends, there being onearm of each pair on each side of the head casting 86. The head casting86 extends to a position alongside the formed tube where it extendsdownwardly from the tube former 8, previously described. By referringnow to Fig. 2 it will be seen that the arms 92 are likewise located toone side of the path of downward` travel of the formed tube. Brackets 94(see Fig. 6 also) are secured to the upper ends of arms 92 and extendlaterally past opposite sides of the path of movement of the formedtube. One of the brackets 94 has fixedly mounted thereon one of the jaws22 comprising a composite jaw assembly 96 comprising upper and lowermembers 98 with a slot or space 100 therebetween. The other bracket 94supports the other jaw 22 and here designated as sealing jaw 102,mounted on the other bracket 94 by means of studs `104, xed to the jaw102 and extending loosely through openings in the other bracket 94. Eachof the studs 104 is provided with a head 106 complementary to a portionof the opening through which the stud extends and each stud is furthersurrounded by compression spring 108 arranged to snugly and firmly seatthe heads 106 in their complementary openings to thereby position thejaw 102 in a predetermined and controlled position in alignment with thejaw 96. The jaws 102 and 96 are provided with suitable heating elementswhereby they are maintained at a sufficiently high temperature to effectheat sealing of the webv 6 when the formed tube is gripped f between thejaws. Springs 108 also insure the correct sealing pressure between thejaws.

In the space 106 between elements 98 of jaw 96, a knife 110 ispositioned. The knife 110 is rigidly fixed to a block 112 (see Fig. 6)which is, in turn, supported by parallel leaf springs 114 from asupporting block 116 fixed to a plate 118 mounted on one of the brackets94.

Thus the knife 110 is mounted for movement ina direction transverse toits length and is maintained by the deu scribed structure in a positionalways parallel to its original position. As will be obvious, movementof the block 112 downwardly as seen in Fig. 6 will cause the knife 110to move outwardly of the slot 100, past the interface between jaws 96and 102, and at least partially into slot 120 in jaw 102. Such movementof the knife 110 will obviously sever the tube clamped between the vjawswith a transverse heat seal above and below the line of severance.

To effect such movement of the knife 110 a bell crank 122 is pivotallymounted on the plate 118, on axis 124 `137 and held in adjusted positionby a hand nut 138.

As the draw bar 18 moves downwardly the jaws described effect thetransverse seal of the formed bag and when the roller 134 passes cam136, lever 130 is swung yin a clockwise direction as seen in Fig. 2,thus moving link 128 to the right. When the link 128 moves to the Irightit swings bell crank 122 (Fig. 6) in a clockwise direction to move block112 downwardly as seen in Fig.

6 and thus the knife 110 is caused to sever the sealed bag.

Referring again to Figs. 3 to 5, each of the shafts 90 6 is providedwith a gear sector 140 fixed thereto. Ac,.- tually, as shown in Fig. 4,the sectors 140 comprise axially spaced concentric sector portions.

equal and opposite pivotal movements of the legs or arms 92 and thusequal and opposite movements of the jaws 96 and 102 relative to theformed tube. The outermost shaft 90 is provided with a further gearSector 142 fixed thereto and extending downwardly into mesh with a shortsection of rack bar 144 fixed on the end of piston rod 146 (see alsoFig. 5). A transverse shaft 148 supports backup rollers 150 bearingagainst the back of rack bar 144 and holding the same in proper meshwith the teeth of sector 142 while permitting longitudinal movementthereof. As shown in Fig. 5, the backup rollers 150 are held in thedesired spaced relationship and in proper relation to the rack bar 144by suitable spacers 152. Y

rl`he piston rod 146 is attached to the piston of a suitablereciprocatory hydraulic motor 154, not shown in detail since it may beof any conventional form. A bracket 156 is secured to the piston rod146, extends outwardly through a slot 158 in a side of the draw bar headstructure and is configured so that its head 160 reciprocates and isarranged to actuate levers 162 and 164 of switches 166 and 168,respectively. The purpose for these switches will be described later.

A post or the like 170 extends laterally from the head casting 86 and ispivotally connected to the lower end of a link 172. The upper end oflink 172 is pivotally connected to a cam bar 174 (see also Figs. 9 and10). The bar 17 4 is supported and guided for rectilinear movement by aplurality of guiding rollers 176 on the inner face of frame plate I32and which rollers engage longitudinal trackways 178 in opposed edges ofthe `bar 174. Thuis, as the pivoted draw bar 18 swings upwardly anddownwardly the cam bar 174 is caused to reciprocate longitudinally intimed relation to movement of the pivoted draw bar and the position ofthe cam bar is indicative of the position of the draw bar. End brackets180 are fixed to the cam bar 174 and support a cam rod 182 in spacedparallel relation to the cam bar 174. A pair of cam brackets 184 are xedto the cam bar 174 and support a cam element 186. The cam element 186 issecured to the brackets 184 by screws 188 passing through slots 190 inthe cam element 186 whereby the latter is 'adjustable longitudinally ofthe cam bar 174. A switch 192 having an operating arm 194 is mounted onthe plate 32 in position to be engaged and actuated by the cam element186. A plurality of cam elements 196, 197, 198 and 1799 are mounted onthe cam rod 162 for selective adjustment therealong and for cooperation,respectively, with fixed switches 200, 202, 204, land 206. A stud 208 isthreaded into the end of cam bar 174 and is threadedly adjustabletherein, being held in a desired position of adjustment by lock nut 210.The stud 208 cooperates with and actuates a further switch 212. Thefunction and purpose for the various switches thus described will bemore fully set forth later. c

Referring again to Figs. l and 2, `and Figs. 6 and 7,

the frame plate 32 carries a housing 214 in which isV journalled a pairof shafts 216. Each of the shafts has a gear sector 218 rigidly fixedthereon and with both gear sectors meshing with a ydouble-faced rack bar220. The rack bar 220 is mounted on a piston rod 222constituting a partof a fluid motor 224. Thus, when fluid motor 224 is actuated toreciprocate a piston therein (not shown) in either direction the rackbar 220 causes gear sectors 218 to rotate shafts 216 in oppositedirections. At its outermost end each shaft 216 carries a 'fitting 226to which a portion of the clipper device 26 is secured.

- Each of the clipper devices is a hollow tubular structure having oneend mounted in one of the fittings 226 and extending generallydownwardly and outwardly therefrom and then vhorizontally outwardly at alevel above The sectors 140 are in mesh with each other and function toinsure.

the uppermost position of the jaws '22. The horizontal portions 230terminate in downwardly extending support portions 232 outwardly of thefree ends of the transverse sealing and clamping jaws 22. The supportportions 232 extend downwardly and are then turned inwardly to formclipper elements 234. The clipper elements 234 extend inwardly onopposite sides of the formed tube. As will be obvious, rocking of theshafts 216 will cause the clipper elements 234 to move toward and fromeach other. The range of movement is from the position shown in Fig. 6where the clipper elements are in substantial contact with each other tolaterally spaced positions of such spacing that the brackets 94 may passbetween the clipper elements with the sealing jaws gripping the formedtube. In like manner the arms supporting the sealing jaws are swingableoutwardly to such an extent that the jaws 93 and 102 can be separated tomove vertically outside the clipper elements 234 even though the latterare not in the fully closed position of Fig. 6, all as will be morefully described later.

Refering again to Fig. 7, the innermost ends of the shafts 216 areprovided with adjustable cams 236 thereon. The cams 236 are arranged tocooperate with fixed switches (not shown) constituting an interlock orsafety feature between different elements of the machine, as will alsobe described in more detail later.

The hopper 2, through which the product is fed into the formed tube, issupported in any suitable manner on the machine and is provided with apair of parallel links 240 pivotally mounted thereon and extending tothe inside of the hopper. A hollow tubular plunger 242 is pivoted to theinner ends of the links 243i) for vertical movement within the hopper.The parts are so proportioned that when the plunger is moved downwardlyabout the xed axes of links 240 its lower end extends into the entranceportion to the formed tube within the tube former 8. The plunger 242 ishollow and open at its lower end and is further provided with an airhose 243 to supply air to the interior of the plunger 242. The lower endof the tubular plunger is open so that air admitted through hose 243 isblown downwardly through the tube former 8. The hose is connected to asupply of cornpressed air through a valve by which the air may beselectively controlled to issue from 242 as a strong blast, as a steadystream, or by which the air may be shut of?.

One of the links 249 is fixed to its pivot shaft 246 which is in turnfixedly connected to the driven core 243 of a exible shaft 250 (shown infragment in Fig. 2). The other end of the flexible shaft core 24S isconnected to a gear 252 meshing with a rack 254 carried by the pistonrod of a pneumatic motor 256. Thus as the piston (not shown) of themotor 256 is driven in one direction, the gear 252 and core 248 arerotated and thus effect downward swinging movement of the link 240 towhich the flexible shaft is connected. Thus downward swinging movementcauses the plunger 242 to move downwardly in the manner previouslydescribed.

The fluid motors 24, 154, 224 and 256 are preferably controlled bysolenoid-operated valves (not shown). The solenoids controlling thosevalves are controlled by the various switches referred to herein andcertain of the valve solenoids are controlled by the photoelectricregistering device 48 previously described. To facilitate illustration,applicant has omitted the valves, solenoids, and circuits therefor sincethe addition of those features to the drawings would render thisdisclosure unduly complicated. It is well within the realm of theskilled mechanic to make the necessary connections and circuits and toprovide the required valves and solenoids to accomplish the functionsand operations described hereafter.

The structures thus far described may be interconnected and controlledin various ways, as will be suggested. A contemplated mode of operationis to arrange the controls so that the photoelectric registry device 48controls a solenoidcperated valve (not shown) which in turn controlsoperation ofhydraulic motor 24 for swinging the draw bar 18 about itsfixed pivot. Thus, as the draw bar moves downwardly it draws the formedtube downwardly and the web 6 past photoelectric device 48 and willcontinue to move downwardly until a registry mark on web 6 actuates thecontrol 43 and results in immediate closing of the iiuid supply valvefor motor 24 to thus stop downward movement of the draw bar 18. At thesame time the control 48 actuates a control valve for fluidmotor 1.54,whereby the jaws 22 are abruptly opened to discontinue drawing the web 6through the tube former at the instant a registry mark reaches theelement 48 and even though the draw bar 18 may continue to movedownwardly, due to inertia or otherwise.

The switches 166 and 163 (Fig. 3) control appropriate solenoid-actuatedvalves arranged to effect opening and/ or closing of the clipper devicesby controlling the flow of actuating lHuid to the fluid motor 224. Theswitch 168, actuated by head when the sealing jaws 96 and 102 are inclosed position, actuates the control valve for motor 224 to open theclippers, that is, to move the clipper elements 234 outwardly away fromeach other. The switch 166 is actuated when the jaws 96 and 102 are intheir open position and effect closing of the clippers. Appropriateelectrical conductors 260 and 262 connect the switches 166 and 168 tothe solenoid-operated valve (not shown). If desired for fast operaticnthe clippers can be caused to close by the control 48, at the time itopens jaws 22.

Referring now to Fig. 9, the switch 192 is arranged to control thedumping of a weighed charge of product into whatever delivery system isemployed for delivering the weighed charge to the hopper 2. The cam 186is so positioned that the charge will be dumped from the weigher at suchtime that it will reach the entrance of the tube former 8 at just aboutthe same instant that jaws 96 and 102 close on the formed tube and startto draw the same downwardly through the former. Thus it is necessarythat the switch E92 be actuated at some time prior to commencement oftube drawing to give the product time to reach the tube so as to movetherewith through the former 8.

The switch 206 is arranged in a circuit to control the pneumatic motor256. Thus the switch 26) is actuated as the draw bar leavessubstantially its upper limit of movement and causes the plunger 242 tomove downwardly to the lower position previously described to break anybridge of product that might have been formed. The plunger 242 is causedto retract by the same signal from control 48 that causes sealing jaws96 and 102 to open. A blast of air through the hollow plungcr 242 isprojected into the tube to distend the same so that the product can fallfreely into the bottom thereof. This blast of air is initiated by thesignal from control 48, and its duration is the period while sealingjaws 96 and 102 are opening. The switch 202 is a draw bar limit switcharranged to stop downward movement of the draw bar 18 in the event offailure of the photoelectric registry device or during operationswherein the web is unprinted or not provided with lbaglength-designating marks thereon. Obviously cam 197' can be preset toactuatc switch 202 after any predetermined or desired distance ofdownward movement of the draw bar and can thus be set to predeterminethe length of successive bags independently of the photoelectriccontrol.

Switch ziiis actuated as the draw bar i8 approaches a limit of itsmovement for the purpose of controlling the uid to motor 24 to effectdeceleration of the draw bar before actual stopping thereof. It wouldobviously be undesirable to stop the relatively heavy draw bar structureabruptly at either end of its movement.

In previous description cams 236 and the ends of shafts 216 for theclipper devices were described as engaging interlock switches. Thoseswitches are arranged in cirassass 9 Y cuit with such a switch as 206 ofFig. 9 and which are also in Aa'circuit controlling the motor 24. Thusunless the switches controlled by the cams 236 are in predeterminedcondition, indicative yof the proper relative positions, the jaws 96 and102 and draw bar 18 cannot beactuated. This safety feature preventsmovement of the* draw bar or jaws at any time when collision with theclippers would result. The detailed arrangement of the cams 236, itsinterlockingswitches and the circuits involved need not be described indet-ail since the arrangements will be obvious to those skilled in theart and their inclusion herein would unduly lengthen and complicate thisdisclosure.

The switch 212, operated by adjustable stud 208, also controls the motor24 to start the draw bar 18 downwardly and initiate a cycle ofoperation. However, the switch 212 is preferably arranged in a circuit(not shown) so that it cannot start operation of the draw bar unless theweighing device associated with the machine has completed a cycle anddelivered a charge of product to this packaging machine. Thus, if acharge of product was not started on its way in time to reach the tubeformer 8 when draw bar 18 reaches its uppermost position, the mereactuation of switch 212 will not initiate another cycle operation of themachine, the draw bar will remain stationary in its upper position untilthe weighing device has cycled and a long enough time interval haselapsed to permit the product to reach tube former 8, then the switch212 will have conditioned the control circuit so that motor 24 canoperate to start a cycle of operation. If the weighing device hasproperly cycled by the time the draw bar reaches its upper limit, theactuation of switch 212 immediately starts another cycle of operation.

It is to be understood that suitable motors or other power devices andpumps are provided to supply the present machine with the necessary airand/or oil under pressure to operate the motors and otherinstrumentalities described. Further, it is obvious that driving meansand controls therefor, other than the fluid motors and valves referredt0, may be used if desired.

As previously described, the clipper devices 26 are formed of hollowtubes. Fig. 1 shows a connection 264 whereby air under pressure may beadmitted to the inv terior of the righthand clipper element 234. It isintended that a similar air conduit be supplied for the lefthand clipperdevice also so that both may be supplied with air under pressure whendesired. The clipper elements 234 are provided with a longitudinallyspaced series of openings on their adjacent inner sides so that air jetsissuing therefrom will impinge upon a tube or bag therebetween, forpurposes to be described hereafter.

Fig. 11 shows a sequence of steps constituting one complete cycle ofoperation of the present machine when arranged for packaging cert-ainproducts, such as, for instance, potato chips. The controls andinterlocks previbusily described yare understood to be so arranged as toeffect the sequences to be described herebelow and it is recognized thatthose skilled in the lart can readily arrange the controls for suchpurposes.

In Fig. 11, sketch A shows the condition of the parts after the dr-awbar has returned to its upper position and defines the commencement of acycle of operation. In this figure the parts are shown in a highlyschematic manner but the reference numerals assigned thereto are thesame as used heretofore in describing the structural ele- Y ments Insketch A the product 270 has settled to the bottom of the formed tube6', draw bar 18 is in its uppermost position with jaws 96 and 102opened, clipper elements 234 `are in an intermediate position, not fullyopened nor fully closed. The longitudinal sealing device 14 isdeenergized andplunger 242 has been retracted from its lowermostposition. Assuming that a charge of product hashleftk the weighingVmachineA and is onv itsway to the 10 hopper 2, the switch 212 willhavebeen closed by the draw bar 18 reaching the uppermost position and anew cycle of operation will have been initiated. To start the cycle ofoperation, the clipper elements 234 close upon the tube immediatelyabove the product therein and 'the jaws 96 and 102 close on the tubeimmediately above the clippers 234 (sketch B). The closing of theclippers iiattens the tube somewhat and expels some of the air from thelower end Ithereof so that a relatively flat iinishedv bag will beproduced. If desired, air can be expelled from the clippers at this timeto impinge on the bag and further assist in attening it. The clippers234 then immediately open to the position of sketch C and the nextcharge of product 270 has just reached the entrance to tube former 8 asthe draw bar 18 starts its downward movement. It is to be noted that, insketch C, the clippers 234 open fully just before the draw bar 18 startsdownwardly so that the clippers will not interfere with the jaws 96 and102 which had closed on the tube above the clippers. Sketch D shows thedraw bar moving downwardly and drawing web material through the tubeformer 8 and the product 270 falling into the tube thus formed. At thistime the plunger 242 has started downward again and air is issuing fromthe lowermost end thereof to distend .the formed tube whereby theproduct 270 may enter the same freely and move downwardly therewith. Insketch E Ithe plunger is shown appreaching its lowermost position andthe draw bar has nearly reached the limit of its downward movement. AtIabout Athis time Ithe knife previously described operates lto sever theformed tube above the lowermost charge of product so that subsequentopening of the jaws will drop a finished sealed lbag of product onto thetake-away conveyor 28. At F eno'ugh web 6 has been drawn to form-another complete bag and photoelectric device 48 has operated to openthe jaws 96 and 102 and thereby terminate dra-.wing of the web materialthrough the tube former. This same photoelectric device 48 operates tostop the downward drive of the draw bar 18 and cause it to decelerate.At the same time the plunger 242 has been drawn to its lowermostposition to insure .the breaking of any bridge of product at theentrance to the tube former and a blast of air is directed downwardlythrough the plunger 242 to distend the formed tube to the practicallimit shown whereby the product '270 may settle as far toward the bottomtherein as possible. As the jaws 96 and 102 start opening toward theposition shown, the web of material stops moving. 'Ihe opening of jaws96 and 102 actuates switch 166, causing the longitudinal sealing device14 to be energized and thus heat-seal the overlapping edges o'f the webmaterial. Switch 166 also causes the clippers 234 to close on .theformed tube above the product 270, as shown in sketch G. By this timethe draw bar 18 has decelerated to its lowermost movement and starts tomove upwardly. It is to be noted at this point that the clippers 234flatten the formed tube at a vposition somewhat below the zone in whichthe next transverse seal will be made. Thus if any of the productextends upwardly into the sealing zone the clippers 234 will break Ithesame and then upon opening to the position of sketch H, the fragmentsare permitted to drop into the bottom of the bag and thus clear the zoneto be transversely sealed without leaving oil, salt or othercontaminants from the product in the zone at which sealing will takeplace.

As shown in sketches H and I, the clippers 234 move .from their yfullyclosed position of sketch G to the intermediate position of sketch H andthen to fully 'closed position at sketch I and to an intermediateposition at sketch I. This particular step or second clip is option-aland is caused by an automatic timing circuit (not shown) well known tothose skilled in the art. This second clip follows `automatically afterinitiation of the first clip described at G. This second clip mayobviously be elimi- ;nated,i f desired. It is to be noted that fromG toKthe draw bar 18 is moving upwardly with its jaws in fully openedposition. After the first clip shown at G and the second clip shown `atI, the clipper elements 234 open only to the intermediate position shownat H, I and K. Thus the draw bar can move upwardly with its jaws fullyopened and there will be no interference between the jaws 96 and 1,62 onthe one hand, and the clipper elements 234 on the other. Thus the jawsmay pass the position of the clippers to the linal position shown at K,which is identical to that shown at A and is the position of starting anew cycle of operation. The longitudinal sealing device 14 remainsenergized from the position of sketch F through that of sketch I but isde-energized at the time the draw bar 18 reaches its upper position tostart a Inew cycle. Immediately following the air blast at sketch F, astream of air continues to blow through the plunger 242 down into thetube to hold the same distended until just prior to the closing of thejaws at the commencement of the next cycle. The clippers may also haveair jets issuing therefrom and impinging on the formed tube in theinterval from H to J to vibrate the tube and cause the product to settletherein. The jets may be in alternating or intermittent blasts and maybe employed in place of the second clip at I.

In the modication shown in Fig. l2, which is a schematic showing, thedraw bar comprises a boxlike structure 272 driven in verticalreciprocation by a pair of hydraulic piston motors 274. The transversesealing and clamping jaws 276 are slidably mounted on opposite sides ofthe draw bar box 272 and moved together or apart by huid motors 278. Theweb of sheet material 280 is fed through the tube former 282 and drawntherethrough byv the draw bar mechanism. A longitudinal seal is providedby sealing means schematically shown at 234. A clipper assemblycomprises pivotally mounted arms 286, pivotally mounted on the machineframe at 288 and moved together or apart by a uid motor 299. At theirouter ends the arms 286 are provided with vertically elongated pivotelements 292 at the lower ends of which clippers 294 are pivotallymounted. The clipper elements 294 are arranged in pairs and are actuatedby means (not shown) Ito open or close in the manner of scissors. 'Therange of movement of the arms 286 is such that the bearing structures292 are always within the vertical projection of the box 272 but movableoutwardly away from the formed tube 296 sufficiently tto clear the endsof the jaws 276. When the arms 286 are moved toward each other to thelimit of their movement, the clippers 294 of each pair extend alongopposite sides of the formed tube .to about the middle thereof so thatthe two pairs of clippers effect clipping completely across the formedtube. With the clipper elements 294 in the open position and .the arms236 at the limit of their movement Itoward each other, the jaws 276 opensuhciently .to clear the ends of the clipper elements 294. The controlmeans and interlocking features described in connection with Figs. lthrough ll may be considered to be present in this modification also,`and the cycle of operation may be scheduled to repeat exactly thosesteps described in connection with Fig. l1.

In the structure described hereinabove, the cycle of operation isdesigned to clip or break portions of the product that extend upwardlyinto the zone of the upper transverse seal. Many products that may bepackaged with :this machine Iare suiciently compact and of such naturethat clipping of the type heretofore described is not necessary. Manysuch products, however, are suciently heavy so that if dropped into thedistended bag as shown at sketch F of Fig. ll, the weight of the productwould in many instances rupture the bottom tnansverse seal, which isstill hot, the sealing jaws having just opened. The present machine andthe clipper structure herein described yis readily adapted to theprevention of such defective operation by arranging the clippers toclose on a bag at a position just above the bottom transverse seals ofsketches F through K; As the draw bar reaches the position of sktech Eand just prior to opening of the sealing jaws, the clippers may beclosed immediately thereabove 1to pinch the formed tube therebetween andeffect a temporary closure thereof above the heat-seal just made. Theclippers will thus be held closed until the product has `dropped to thebottom of the bag, the weight thereof being supported by the closedclippers rather than by the hot seal. The clippers could be re tained inthe closed position during upward movement of the draw bar and openedjaws and held in closed position until the draw bar starts its downwardmovement at the next cycle, -thus giving the transverse heatseal themaximum amount of time to cool and harden before the weight of theproduct is applied thereto. The clippers would then open long enough topermit passage of the jaws therebetween and then close again to repeatthe described cycle.

The various modifications of apparatus shown and described herein areobviously adapted to other modes `and cycles of operation from thosespecifically set forth and described. It will be obvious to thoseskilled in the art that the sequence of steps or the nature ofsuccessive steps may be modified by using the same basic apparatus shownherein and it is contemplated that other modes of operation beencompassed within the scope of the appended claims.

I claim:

l. In a packaging machine; tube-forming means, means for guiding acontinuous web of material through said tube-forming means to form alongitudinally sealed tube, cyclically operable means for forming atransverse seal across said tube and for drawing a predetermined lengthof material through said tube-forming means; means for periodicallyfeeding product into said tube in timed relation to operation of saidcyclically operable means; clipper means comprising elements extendingtransversely of said tube on opposite sides thereof and mounted formovement toward and from each other to atten said tube therebetween,means responsive to movements of said cyclically operable means forcontrolling operation of said clipper means, said cyclically operablemeans including opposed sealing and clamping jaws extending transverselyof said tube on opposite sides thereof, and means mounting each of saidjaws with at least one end thereof free, said clipper elements beingcarried by means extending outwardly of said free ends of said jawswhereby said jaws may move longitudinally of said tube either betweensaid clipper elements or outwardly thereof.

2. A machine as defined in claim 1 wherein said jaws clampingly engagesaid tube to form a transverse seal at a position closely adjacent saidclipper means but spaced therefrom in a direction away from a previouslyformed transverse seal.

3. In a packaging machine; tube-forming means, means for guiding acontinuous web of material through said tube-forming means to form alongitudinally sealed tube, a draw -bar device comprising an arm mountedfor swinging movement about a xed axis spaced laterally of said tube, aportion of said arm being movable along lan arcuate path adjacent andgenerally tangent to the axis of said tube, relatively movable jaws onsaid portion of said arm for gripping and pulling said tube through saidtube-forming means, and driving means for cyclically swinging said armabout said fixed axis.

4. A machine as defined in claim 3 wherein said driving means comprisesa reciprocatory fluid motor.

5. A machine as dened in claim 3 wherein said portion of said armextends alongside said tube, said jaws being pivotally mounted on saidarm on spaced axes and extending laterally thereof on opposite sides ofsaid tube, and operating means for simultaneously swinging said jaws inopposite directions about said spaced axes.

6. Amachine as defined in claim 3 wherein said driving 13 meanscomprises a selectively reversable motor device, and detecting meansadjacent said web of material for de tecting the advance of apredetermined length thereof and for controlling said motor device.

7. A machine as defined in claim 3 including a control cam devicemovably mounted on said machine, and means drivingly connecting said armto said control cam device for controlling the opera-tion of portions ofsaid machine in timed relation to the movements of said arm.

8. A machine as dened in claim 7 wherein said control cam devicecomprises an elongated bar, means guiding said bar for longitudinalrectilinear movement on said machine, a rod, means mounting said rod onsaid bar in spaced parallel relation thereto, a plurality of switchesadjacent said cam device, and -a plurality of cams adjustable along saidrod and said bar vand respectively engageable with said switches tooperate the same and thereby control the operation of said portions ofsaid machine.

9. In a packaging machine; tube-forming means at one side of a portionof said machine, means for guiding a continuous web of material4downwardly through said tube-forming means to form a longitudinallysealed tube, cyclically operable means mounted for generally verticalmovement on said side of said portion of said machine, below saidtube-forming means and having a pair of tubegripping and sealing jawsthereon, said jaws extending outwardly of said side and terminating infree outer ends, a pair of clipper devices pivotally mounted on saidportion on spaced axes above said jaws, each of said clipper devicesincluding a support portion extending outwardly of said side above saidjaws and then downwardly outwardly of the free ends of said jaws, and aclipper portion on the'lower end of said support portion and ex,

14 tending inwardly toward said side and below said jaws whereby saidjaws may be moved toward or from each other between said supportportions and said clipper portions and 4also in said generally verticaldirection either between or laterally outwardly of said clipperportions.

' l0. In a packaging machine; tube-forming means,

means for guiding a continuous web of material through` f saidtube-forming means to form a longitudinally sealed tube, cyclicallyoperable means for forming a transverse seal across said tube and fordrawing a predetermined length of material through said tube-formingmeans; and clipper means comprising elements extending transversely ofsaid tube on opposite sides thereof and mounted for movement toward andfrom each other to substantially completely flatten said tubetherebetween, said clipper ele ments being hollow and provided withoutletopenings on the sides thereof adjacent said tube, and means forsupplying air under pulsing pressure to the interiors of said hollowelements whereby pulsing jets issuing from Y said outlet openingsimpinge on the sides of. said tube.

References Cited in the iile of this patent UNITED STATES PATENTS

